I'm putting together a PC for someone I know (this, btw, is the same PC that I asked about on my DVI thread earlier today). It's assembled, but it won't run XP. The HD is a PATA Seagate 500GB. It completes the first DOS-like portion of XP setup, but when it restarts, it tells me "Error loading operating system." Now the funny thing is that when I slip in my Vista DVD, everything works just fine, so the HD can't be bad. But the guy I'm building this for wants XP instead of Vista. I'm at a loss. Any ideas? Pentium III--Descendant of Intel Core. Pentium III-S 1400 @ 1.63GHz, 512K L2 X800XT AIW OC 580/600 2GB of RAM 250GB HD SB Audigy 2 QDI Advance 12 mobo Smugly running Vista

You could try obtaining a new license key and see if that helps. (By the way, how well is that Pentium III running Vista? =D.) I like chicken.

The "error loading OS" comes up before Windows even shows its splash screen. I really doubt that a new license key would help me. My beloved P3 is running Vista just great, thanks! What many people don't know about the P3 (and especially the Tualatin-based P3-S) is that they do a lot more work per clock cycle than P4s. At 1.63GHz, this thing is running as fast as a P4 at 2.5GHz in everything except video encoding. Pentium III--Descendant of Intel Core. Pentium III-S 1400 @ 1.63GHz, 512K L2 X800XT AIW OC 580/600 2GB of RAM 250GB HD SB Audigy 2 QDI Advance 12 mobo Smugly running Vista

Have you tried different "XP media"? I have noticed with my XP installs that although during the initial part of the install (just after formatting the drive/partition) it says copying files to hard drive, that after the first reboot it continues to access the CD. Also, it may be related to the 48-bit LBA problem. What is the size of the partition you are trying to load it to? If you are trying to do a partition larger than 120GB you need to be installing from an XP cd that includes at least Service Pack one slipstreamed into it.

Have you tried installing the raid drivers for your SATA HD???

First thought would be a corrupted CD, but I'm guessing it's got through the 'copying files' section ok so that shouldn't be a problem. You could try installing it on a smaller partition rather than the full 500Gb - stranger things have happened. May be worth running a manufacturer's diagnostic on the harddrive itself anyway just to be sure. "I've always been mad, I know I've been mad, like the most of us..."

johnr, installing XP on a 20GB partition worked great! Thanks for your help! Pentium III--Descendant of Intel Core. Pentium III-S 1400 @ 1.63GHz, 512K L2 X800XT AIW OC 580/600 2GB of RAM 250GB HD SB Audigy 2 QDI Advance 12 mobo Smugly running Vista